Clamshell assembly

ABSTRACT

A clamshell assembly in which both jaws may be actuated by a single hydraulic cylinder and in which the entire assembly may be rotated in a horizontal plane through a chain drive which is actuated by two cooperating hydraulic cylinders.

O Unlted States Patent [:11 3,5 ,3 2

[72] Inventor Sam Kramer [56] Reieren e Cited 2591 South R001 RiverParkway, west UNITED STATES PATENTS 53227 2,604,220 7/1952 Frischmann294/88 X [2]] Appl. No. 744,926

. 2,812,970 l1/1957 Martmson 294/71 [22] Filed July 15, 1968 [45] PaemedJune 22 197 2,621,428 12/1952 BllllngS 37/187 2,725,996 12/1955Britton... 214/147(G) 3,080,988 3/1963 Redman 214/656 3,413,029 11/1968Donovan 294/70 Primary Examiner-Gerald M. Forlenza AssistantExaminerRobert J. Spar 1541 CLAMSHELL ASSEMBLY Ammeksam 3 Claims, 4Drawing Figs.

[52] U5, C1 294/70, ABSTRACT: A clamshell assembly in which both jawsmay be 214/147 G actuated by a single hydraulic cylinder and in whichthe entire (51 Int. Cl B66c 3/02 assembly may be rotated in a horizontalplane through a chain [50] Field of Search 214/138, drive which isactuated by two cooperating hydraulic cylinders.

CLAMSHELL ASSEMBLY BACKGROUND OF THE INVENTION 1. Field of the InventionThe invention pertains to clamshell buckets.

2. Description of the Prior Art The commercially employed clamshellbuckets which were used prior to the present invention employed twohydraulic cylinders, with each cylinder being used for each bucket ofthe clamshell. The present invention eliminates one of the cylinders andobtains movement of both buckets by interconnecting the buckets througha linkage.

Also, the clamshell buckets employed commercially prior to the presentinvention were usually not rotatably mounted to the boom of the back hoeor similar construction equipment.

In some instances in which rotational mounting was provided, themounting structure was quite complicated and expensive. The presentinvention eliminates the cumbersome prior art structures.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide an extremely versatile clamshell bucket without employingcomplicated or cumbersome mechanisms.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side plan view of the clamshellbucket embodying the present invention;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side plan view taken on line 33; and

FIG. 4 is a diagrammatic view of the mechanism employed to rotate theclamshell assembly in respect to the boom.

DESCRIPTION OF THE PREFERRED EMBODIMENT The major components of theclamshell bucket embodying the present invention are a sprocket wheelassembly which is fixedly connected to a boom (not shown) of the backhoe, a frame 12 which is mounted for rotation around the sprocket wheelassembly, jaws l4 and 16 which are pivotally mounted at the lower end ofthe frame, a double-acting hydraulic cylinder 18 for closing and openingof the jaws, and two hydraulic cylinders 20 and 22 which are operable torotate the frame in respect to the sprocket wheel assembly.

The sprocket wheel assembly 10 is comprised of an eye member 24 and twokey members 25 and 26 all of which are welded to a supporting member 27.These elements serve to fix the sprocket assembly to the boom, and inthemselves do not form an essential part of the present invention. Asprocket wheel 28 is welded to the lower face of the supporting memberand a threaded shaft 29, which is also fixed to the supporting member27, projects through a bushing 30 which is fixed in the top plate 31 ofthe frame 12. The sprocket wheel assembly 10 is secured to the frame 12via a bearing plate 32 which is mounted on the lower projecting portionof the shaft 29. The frame, although being secured to the sprocket wheelassembly, is free to rotate in a horizontal plane in respect thereto.

The frame 12 has two downwardly extending legs 34, 34 each of which arefixed to the top plate 31 and terminate at two spaced-apart bushings 36which receive the rightand left-hand jaw pivot pins 38 and 39. Thehydraulic cylinder 18 is bolted to the inside faces of the legs 34 andis free to pivot around its mounting pin 40. The ram of the cylinder 18is pivotally connected by pin 41 to two upwardly extending flanges 42 ofthe jaw 14. The flanges 42 extend further inwardly towards the center ofthe clamshell bucket and are pivotally connected by pin 43 to link 44which in turn is connected to two upstanding flanges 46 of jaw 16 by pin45. A jaw-scraper assembly, which is comprised of a rectangular frame47, is positioned inside the jaws and is connected on both of its sidesto pins 39 and 38 by eye members 48.

As the cylinder IS retracted from the position shown in FIG.

1, it causes jaw 14 to pivot in a counterclockwise direction around pin38. Simultaneously, link 44 imparts an equal clockwise motion to jaw 16as it pivots around pin 39. During the movement of jaws l4 and 16, thejaw-scraper assembly remains stationary in respect to the frame 12 andthereby causes the frame 47 to scrape along the sides and bottoms of thejaws.

The hydraulic cylinders 20 and 22 are fixed within channel sections 50,50 which are welded to the upper ends of the frame legs 34. The pistonof each of these cylinders carries a small horizontally disposedsprocket wheel 51 which is engaged by a chain 52. The chain is anchoredat both of its ends to lugs 53 which are fixed to the channel sections50. .The chain extends partially around the small sprocket wheels 5l aswell as around the sprocket wheel 28 of the fixed sprocket wheelassembly 10. A second chain 54 is fixed at both of its ends to tabs 55,which are fixed to the pistons of cylinders 20 and 22, and extendsaround horizontally positioned sprocket wheels 56, 56 which are fixedwithin a channel section 58 which is connected at both of its ends tochannel sections 50, 50.

The above-described arrangement of the sprocket wheels and chains 52 and54 permits unlimited turning of the clamshell assembly through 90 andassures positive engagement between chain 52 and the sprocket wheel 28.To rotate the clamshell assembly in a clockwise direction from theposition shown in FIG. 2, the piston of cylinder 22 is retracted andsimultaneously the piston of cylinder 20 is extended. Because thepistons of both cylinders are interconnected by chain 54, equal travelof both pistons is assured and thus slackening or disengagement of thechain 52 from sprocket wheel 28 is impossible.

Although but a single embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. A clamshell assembly having:

a frame with jaw means pivotally attached thereto and having meansincluding a support member adapted to attach the clamshell assembly tothe boom of a construction machine, said attachment means comprising;

a main sprocket wheel and means for fixedly attaching said main sprocketwheel to the support member;

bearing means connecting said frame to said main sprocket wheel forrotational movement in a horizontal plane in respect thereto;

two hydraulic cylinders fixed to said frame at opposing sides of saidmain sprocket wheel and each of said cylinders being provided with aseparate sprocket wheel which is attached to the respective pistons ofthe cylinders; and

a chain fixed at both of its ends to said frame and extending over andengaging the sprocket wheels of said cylinders and under the mainsprocket wheel therebetween to cause rotation of said frame in respectto said main sprocket wheel upon outward movement of one of saidcylinders and simultaneous inward movement of the other of saidcylinders.

2. A clamshell assembly and attaching means according to claim 1 whereinsaid pistons of said two cylinders are interconnected by means assuringsimultaneous and equal speed of movement of said two pistons.

3. A clamshell assembly and attaching means according to claim 2 whereinsaid interconnecting means is comprised of two sprocket wheels which arefixed to said frame and a chain which engages said last-mentionedsprocket wheels and which is fixed at each of its ends to said pistonsof said two cylinders.

1. A clamshell assembly having: a frame with jaw means pivotally attached thereto and having means including a support member adapted to attach the clamshell assembly to the boom of a construction machine, said attachment means comprising; a main sprocket wheel and means for fixedly attaching said main sprocket wheel to the support member; bearing means connecting said frame to said main sprocket wheel for rotational movement in a horizontal plane in respect thereto; two hydraulic cylinders fixed to said frame at opposing sides of said main sprocket wheel and each of said cylinders being provided with a separate sprocket wheel which is attached to the respective pistons of the cylinders; and a chain fixed at both of its ends to said frame and extending over and engaging the sprocket wheels of said cylinders and under the main sprocket wheel therebetween to cause rotation of said frame in respect to said main sprocket wheel upon outward movement of one of said cylinders and simultaneous inward movement of the other of said cylinders.
 2. A clamshell assembly and attaching means according to claim 1 wherein said pistons of said two cylinders are interconnected by means assuring simultaneous and equal speed of movement of said two pistons.
 3. A clamshell assembly and attaching means according to claim 2 wherein said interconnecting means is comprised of two sprocket wheels which arE fixed to said frame and a chain which engages said last-mentioned sprocket wheels and which is fixed at each of its ends to said pistons of said two cylinders. 